Donald Trump risks taking the blame for a global recession if he continues his trade war with China, the UK prime minister Boris Johnson said ahead of their meeting at the G7 summit.

The two leaders met for breakfast in Biarritz on Sunday morning. In advance of their meeting, Johnson warned Trump that his trade war was “not the way to proceed,” and risked pushing the global economy into a downturn.

“Apart from anything else, those who support the tariffs are at risk of incurring the blame for the downturn in the global economy irrespective of whether or not that is true,” he told reporters on Saturday.

He said other countries, including the UK are “at risk of being implicated in this.”

“We [the UK] face tariffs of altogether £2.25 billion – that’s the value of the goods affected, £1.1 billion on whisky alone – that we could face if this goes on. This is not the way to proceed.”

He called on the president to change tack and go for an “opening up of global trade,” instead.

“I want to see a dialling down of tensions and I want to see tariffs come off,” he said.

Johnson also urged Trump to drop restrictions on UK goods entering US markets as part of a potential post-Brexit trade deal.

“It’s not just beef or lamb that is currently banned from entering the US, in spite of their commitment to overturn that prohibition in 2014,” Johnson said.

“Melton Mowbray pork pies, which are sold in Thailand and in Iceland, are currently unable to enter the US market because of some sort of Food and Drug Administration restriction.”

Speaking to reporters ahead of their meeting, Trump praised Johnson as the “right man” to deliver Brexit.